The present invention relates to the field of electric ceiling fans.
Electric ceiling fans are widely used for their ability to move and circulate air within a room. Manufacturers of electric ceiling fans offer numerous fan designs for their customers. Many designs have only aesthetic differences. However, some ceiling fan designs possess certain functional features that differentiate the fan from other fans.
One ceiling fan design that existed in the past is a ceiling fan with retractable fan blades. An example of such a ceiling fan is shown in U.S. Pat. No. 1,445,402 to Le Velle. This fan design includes an electric motor held within a motor housing and a plurality of fan blades. Each of the fan blades include one end pivotally attached to a rotor and an opposite free end. When the motor is not spinning the rotor, the fan blades are folded inward and interleaved near the motor housing. When the motor spins the rotor, centrifugal forces on the blades push the free end of the blades outward into an extended position away from the housing.
Some consumers may enjoy this design feature of retractable fan blades where the fan blades are largely hid from view when the fan is not in use. If an electric light is attached to the motor housing, the apparatus appears to be only a light when the fan is not in use. Accordingly, the retractable fan blade feature is particularly desirable to those who do not wish to see static fan blades in a room when the ceiling fan is not in use.
One problem with this type of existing ceiling fan design is that the blades tend to be somewhat unstable when moving between the folded position and the extended position. In particular, the fan blades tend to wobble while unfolding. The wobbling fan blades not only give an unstable appearance to the fan, but also produce an undesirable clunking noise. Accordingly, it would be desirable to provide a fan with retractable blades wherein the blades are stable appearing unfolding and do not produce the above-described undesirable noise.
Another problem with this type of ceiling fan design is that the blades tend to quickly move between the folded position and the extended position. This rapid outward movement of the fan blades not only produces a relatively loud noise when the blades reach their extended position, but also make the fan momentarily appear as if it were somewhat unstable. Individuals not expecting this rapid movement and relatively loud noise may be startled, making the fan undesirable to use. Accordingly, it would be desirable to provide a fan with retractable blades where the blades slowly move between the folded and unfolded positions with little noise and do so in a stable appearing manner.